1. Field of the Invention
The present invention concerns a method for controlling the acquisition and/or evaluation operation of image data in medical examinations.
2. Description of the Prior Art
In routine organ examinations (in particular with a magnetic resonance apparatus) the physician must manually set the acquisition regions for acquisition of a target area surrounding the organ. This usually occurs using scans that are acquired anyway (known as localizers) that (often in low resolution and formed of only a few slices) should serve for location of the target area. The user thereupon views these localizer exposures displayed on a suitable display means and therein places the acquisition areas manually.
If the target volume or organ is arranged in a target area that moves in a cycle, for example due to respiration or heart activity, navigators are frequently also placed. Navigators are markings that mark a specific small region of the target area in which important parameters for the acquisition are then determined. For example, it is known to set a navigator through which a clearly recognizable edge contour of the considered organ proceeds substantially perpendicularly. When the patient breathes, the edge of this organ cyclically shifts with the respiration movement such that the respiration phase is concluded from the current position of this edge and can be used, for example, for triggering or to determine the respiration phase. With rapidly operating systems it is even possible to also implement these observations for the heart phase. One- or three-dimensional navigators are also known in which a point or a whole surface piece is considered. In order to make full use thereof, these navigators must be set exactly; in particular in the above case, the borders of the organ must be perpendicular to the navigator.
Moreover, such markings are also effected in the form of regions of interest in image data sets given the evaluation of these image data sets. For example, organs segmented manually and provided with an identifier so that distinctive features (landmarks) can be associated with them. Such manual markings are frequently also necessary in the region of the start points and borders for segmentations.
Such manual markings or selection processes are, however, generally very error-prone. For example, systems with which localizer exposures are used are particularly error-prone, since the resolution and slice count are usually low and the entire target volume is not covered by them. The exact positioning of the mentioned navigators is likewise critical and error-prone. In addition to the mentioned tendency toward error, the high time expenditure for such a manually implemented procedure is a further disadvantage of the known procedure.